<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .fa{
            width: 200px;
            height: 200px;
            background-color: red;
        }
        .son{
            width: 10%;
            text-align: center;
            background-color: gray;
        }
    </style>
</head>
<body>
    <div class="fa">
        <div class="son">X</div>
    </div>

    <script>
        const son = document.querySelector('.son')
        son.addEventListener('click',function(){
            son.parentNode.style.display = 'none'
        })
    </script>
</body>
</html>